JPH05321663A - Cooling fan fitting structure - Google Patents

Abstract

PURPOSE:To avoid the deformation or damages of a cooling fan without causing the large increase in the cost or the weight in a cooling fan structure where a cooling fan is provided to the end part of a crankshaft in a vehicle such as a truck. CONSTITUTION:A cooling fan 5 to execute the air-cooling of a radiator of an engine is provided to the end part of a crankshaft of the engine through a friction clutch 16. The transmission torque capacity of the friction clutch 16 is larger than the maximum fan driving torque in the normal load condition of the cooling fan 5, and smaller than the fan driving torque in the super-load condition of the cooling fan 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan for radiator air cooling suitable for use in an engine of a vehicle such as a truck, and more particularly to a cooling fan mounting structure in which a cooling fan is mounted on an end of a crankshaft. ..

[0002]

2. Description of the Related Art FIG. 2 is a schematic vertical sectional view showing a general engine mounting state in a truck. As shown in FIG. 2, an engine 3 is mounted below a floor portion 2 which constitutes a cabin 1. Has been done. Then, as shown in the schematic front view of FIG. 2, a cooling fan 5 is attached to a tip end portion of the crankshaft 4 protruding from the engine 3 toward the front side of the vehicle.

That is, as shown in the schematic side view of FIG. 3, a crank pulley 6 is fixed to an end portion of a crank shaft 4, and a cooling fan 5 is separated from the crank pulley 6 by a spacer 7 by a required amount. And are fixed to the spacer 7 by bolts 8. The cooling fan 5 has a structure in which a resin-made fan body 5B is formed on a sheet metal base 5A in order to reduce the weight, and the resin-made fan body 5B is necessary for securing a cool air flow. It has the required strength for rotation.

[0004]

By the way, in the case of such a conventional cooling fan mounting structure, since the crankshaft 4 of the engine 3 is located at a low position, the cooling fan 5 has its peripheral end close to the road surface. It is equipped in the state. Therefore, when the road surface is flooded or when running in shallow water, the cooling fan 5 scrapes the water, and the blade load becomes about 1000 times the normal load, which may cause deformation or damage of the cooling fan 5. There is a challenge of inviting.

This can be avoided by raising the position of the cooling fan 5, and for example, as shown by the chain line in FIG. 2, the structure in which the cooling fan 5 is attached to the water pump 23 arranged above the engine is also provided. Existing.
However, if the position of the cooling fan 5 is moved upward in this way, the floor portion 2 of the cabin 1 interferes with the cooling fan 5. Therefore, in order to secure a rotation space for the cooling fan 5, the floor of the cabin 1 must be secured. The part 2 must be set higher or the floor part 2 must be partially deformed.

However, making the floor portion 2 higher makes the interior space of the cabin 1 narrower and lowers the habitability, and the floor portion 2 is partially deformed, so that the floor is not flat and the habitability is low. Result in a decrease. Therefore, as shown in the schematic side view of the main part of FIG. 4, it is conceivable to interpose an autocool fan coupling 9 between the cooling fan 5 and the crank pulley 6. In addition,
The cooling fan 5'has a structure in which a resin fan body 5B is formed on a sheet metal base 5A '.

This Autocool fan coupling 9
5 is configured as shown in the schematic vertical sectional view of FIG. 5, in which a disk 13 is provided inside a casing 10 and silicone oil 11 having a high viscosity is filled.
The disk 13 is connected to one end of a rotating shaft 14, and the casing 10 is rotatably attached to the rotating shaft 14 via a bearing 15, and the other end of the rotating shaft 14 is connected to the crank pulley 6. The rotation of the crankshaft 4 is transmitted to the disc 13 via the rotary shaft 14.

An autocooling mechanism 12 is attached to the end surface of the casing 10, and the silicone oil 11
The amount in the casing 10 is controlled according to the outside air temperature. The base 5A 'of the cooling fan 5 is fixed to the casing 10, and the cooling fan 5 is connected to the crank pulley 6 via the silicone oil 11 in the casing 10.

Therefore, the rotation of the crank pulley 6 is transmitted to the cooling fan 5 by the fluid friction due to the viscosity of the silicon oil 11. As a result, the normal rotation of the cooling fan 5 without scratching the water is performed without any trouble. On the other hand, when the cooling fan 5 is scraping water, slippage of the silicone oil 11 prevents the cooling fan 5 from rotating unreasonably, and the disk 13 spins in the casing 10 to prevent the cooling fan 5 from rotating. Deformation and damage are avoided.

Therefore, if the auto-cool fan coupling 9 as described above is provided, the above-mentioned problems can be solved.
However, the equipment for the auto-cool fan coupling 9 involves a large cost increase and an increase in weight, which poses a problem as equipment for trucks and the like.

The present invention has been devised in view of the above problems, and provides a cooling fan mounting structure capable of avoiding deformation and damage of the cooling fan without causing a large increase in cost and weight. The purpose is to provide.

[0012]

Therefore, according to the cooling fan mounting structure of the present invention, a cooling fan for air-cooling a radiator of an engine is mounted on an end portion of a crankshaft of the engine through a friction clutch, and The transmission torque capacity of the clutch is set to be larger than the maximum fan drive torque when the cooling fan is under normal load and smaller than the fan drive torque when the cooling fan is overloaded.

[0013]

In the cooling fan mounting structure of the present invention described above, during normal operation, the cooling fan is rotationally driven by the crankshaft via the friction clutch, and the cooling fan receives resistance from water due to flooding, etc. Then, the fan driving torque becomes larger than the transmission torque capacity, and the friction clutch releases the transmission of the driving force from the crankshaft to the cooling fan.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling fan mounting structure as one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of an essential part showing the structure. As shown in FIG. 1, in an engine, a cooling fan (cooling fan) 5 is attached to an end portion of a crankshaft 4 via a crank pulley 6 and a spacer 7 (see FIG. 3). The cooling fan 5 has a structure in which a resin-made fan body 5B is integrally formed with a sheet metal base 5A in order to reduce the weight, and the resin-made fan body 5B is used for securing a cool air flow. It has the required strength to support the required rotation.

Then, the spacer 7 and the cooling fan 5
A single-plate friction clutch (hereinafter referred to as a plate friction clutch) 16 is interposed between and so that the transmission of the driving force is released in the overloaded state from the crankshaft 4 to the cooling fan 5. It has become. It should be noted that this overload state is a state in which the resistance of the cooling fan 5 is significantly higher than the fluid resistance received from the air when the cooling fan 5 is rotated in the air. This is the case when the fluid resistance is received from.

That is, the plate friction clutch 16 includes the clutch plate 19 on the spacer 7 side and the cooling fan 5.
It is configured by frictionally engaging the disk portion 21 of the side base 5A. The coil spring 20 is interposed between the back surface of the clutch plate 19 and the stepped end surface of the spacer 7.
Is urged by the coil spring 20 and pressed against the disc 21, so that the frictional engagement state between the clutch plate 19 and the disc 21 is maintained.

By the way, a mounting hole portion 22 is provided in the axial center portion of the disk portion 21 of the base 5A, and the mounting hole portion 22 is mounted on the tip of the spacer 7. Further, a retainer 17 is fastened and fixed to the tip of the spacer 7 with a bolt 18, and the mounting hole 22 is fitted in an annular groove formed between the retainer 17 and the spacer 7. As a result, the disk 21 is axially locked while contacting the retainer 17, and the biasing force of the coil spring 20 to the clutch plate 19 and the disk 21 is supported.

The transmission torque capacity of the plate friction clutch 16 is set to be larger than the maximum fan drive torque when the cooling fan 5 is normally loaded and smaller than the fan drive torque when the cooling fan 5 is overloaded. ing. The biasing force of the coil spring 20 is
The transmission torque capacity of the plate friction clutch 16 due to the frictional engagement between the clutch plate 19 and the disc 21 is larger than the maximum fan drive torque when the cooling fan 5 is normally loaded, and when the cooling fan 5 is overloaded. It is set smaller than the fan drive torque.

That is, during normal operation under a load such that the cooling fan 5 drives the cooling air flow, the plate friction clutch 16 does not slip and the cooling fan 5 rotates together with the spacer 7 so that the coil spring 20 can rotate. The urging force of is set. In addition, when the cooling fan 5 receives an excessive load that tends to deform or damage the cooling fan 5, the clutch plate 19 and the disc 21 cannot hold frictional engagement and slip out. Twenty biasing forces are set.

Since the cooling fan mounting structure as one embodiment of the present invention is constructed as described above, during normal operation in which the cooling fan 5 drives the cooling air flow by the required amount, the plate friction clutch 16 The frictional engagement between the clutch plate 19 and the disc 21 due to the urging force of the coil spring 20 is maintained, and the cooling fan 5 rotates together with the spacer 7 as required.

For example, when the cooling fan 5 tries to rotate so as to scrape up the water when traveling on a flooded road surface or in shallow water, the load on the cooling fan 5 becomes excessive and the coil spring 20 The urging force
The frictional engagement between the clutch plate 19 and the disc 21 cannot be maintained. Therefore, the plate friction clutch 16 slides out, the friction engagement state is released, and the cooling fan 5 is released.
The clutch plate 19 on the side of the spacer 7 idles in a state where the rotation is locked by water.

As a result, in the overloaded state of the cooling fan 5, the transmission of the driving force is released, and the cooling fan 5 is prevented from being deformed or damaged. Since the plate friction clutch 16 in this structure has a simple structure, it is not necessary to use the silicone oil 11 as in the autocool fan coupling 9, and the sealing structure of the silicone oil 11 is unnecessary. , Can be manufactured at low cost.

Further, the plate friction clutch 16 may be mainly equipped with the coil spring 20 and the clutch plate 19, and the increase in weight can be suppressed to the minimum. Therefore, according to this structure, the object can be achieved at low cost and without causing a significant increase in weight.

[0024]

As described above in detail, according to the cooling fan mounting structure of the present invention, the cooling fan for air-cooling the radiator of the engine is mounted on the end portion of the crankshaft of the engine via the friction clutch. Due to the extremely simple structure, the transmission torque capacity of the friction clutch is set to be larger than the maximum fan drive torque of the cooling fan at the time of normal load and smaller than the fan drive torque of the cooling fan at the time of overload. However, there is an advantage that the deformation and damage of the cooling fan can be avoided at low cost and without causing a significant increase in weight.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part schematically showing the structure of a cooling fan mounting structure as one embodiment of the present invention.

FIG. 2 is a schematic vertical cross-sectional view showing a general engine mounted state in an automobile (truck).

FIG. 3 is a schematic side view showing an example of a conventional cooling fan mounting structure.

FIG. 4 is a schematic side view showing another example of a conventional cooling fan mounting structure.

FIG. 5 is a vertical cross-sectional view of an essential part schematically showing an auto-cool fan coupling provided in a conventional cooling fan.

[Explanation of symbols]

 1 Cabin 2 Floor part 3 Engine 4 Crankshaft 5 Cooling fan 5A Base 5B Fan body 6 Crank pulley 7 Spacer 8 Bolt 9 Autocool fan coupling 10 Casing 11 Silicon oil 12 Autocool part 13 Disc 14 Rotating shaft 15 Bearing 16 Plate Friction clutch 17 Retainer 18 Bolt 19 Clutch plate 20 Coil spring 21 Disc part 22 Mounting hole 23 Water pump

Claims (1)

[Claims] 1. A cooling fan for air-cooling a radiator of an engine is attached to an end portion of a crankshaft of the engine through a friction clutch, and a transmission torque capacity of the friction clutch is maximum when the cooling fan is under normal load. The cooling fan mounting structure is set to be larger than the fan driving torque of the above and smaller than the fan driving torque when the cooling fan is overloaded.